Ok, ok, so what’s the big deal? This is just Rails’ default database configuration. Well, that’s the
point -- you no longer have to know anything about JDBC URLs, driver class names, and all that. We’ve baked it in for you. This should make it easier than ever to try out your Rails application on JRuby, as the only piece of manual configuration left for you is the ugly bit of JRuby-specific code you need to activate ActiveRecord-JDBC lurking right above the Rails::Initializer: